#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

#define For(i, a, b) for(i = (a); i <= (b); i++)

#define NMax 100010
#define LMax 20

int n, m;
int h[NMax << 1], l[NMax << 1], lg[NMax << 1], First[NMax];
int k = -1;
int rmq[NMax][LMax];

vector<int> G[NMax];

void dfs(int x, int lev);
void init_rmq();
int lca(int, int);

int main(){
	int i, x, y;
	
	fin >> n >> m;
	For(i, 2, n){
		fin >> x;
		G[x].push_back(i);
	}
	
	dfs(1, 0);
	
//	For(i, 0, k) cout << h[i] << ' ';
//	cout << endl;
//	For(i, 0, k) cout << l[i] << ' ';
//	cout << endl;
	
	init_rmq();
	
	while(m--){
		fin >> x >> y;
		fout << lca(x, y) << '\n';
	}
}

void dfs(int x, int lev){
	h[++k] = x;
	l[k] = lev;
	First[x] = k;
	for(int i = 0; i < G[x].size(); i++){
		dfs(G[x][i], lev + 1);
		
		h[++k] = x;
		l[k] = lev;
	}
}

void init_rmq(){
	int i, j, m;
	
	For(i, 0, k) rmq[i][0] = i;
	for(j = 1; (1 << j) < k; j++){
		for(i = 1; i + (1 << j) <= k; i++)
			if(l[rmq[i][j - 1]] < l[rmq[i + (1 << (j - 1))][j - 1]])
				rmq[i][j] = rmq[i][j - 1];
			else 
				rmq[i][j] = rmq[i + (1 << (j - 1))][j - 1];
	}
}

int lca(int a, int b){
	int poz;
	a = First[a];
	b = First[b];
	if(a > b) swap(a, b);
	int lg = (int)log2(b - a + 1);
	if(l[rmq[a][lg]] < l[rmq[b - lg + 1][lg]]) poz = rmq[a][lg];
	else poz = rmq[b - lg + 1][lg];
	return h[poz];
}